Cell elongation induced by ftsZ antisense RNA expression in Escherichia coli strain DH5ɑ increases T4 bacteriophage adsorbed per cell

Abstract

Adsorption is a fundamental step in the bacteriophage life cycle that results in the irreversible attachment to external asperities on the cell surface of Escherichia coli, allowing for the eventual injection of the viral genome for replication. Previous research has demonstrated that E. coli grown in rich media were larger and adsorbed more T4 bacteriophage than cells that were grown in less carbon-rich media. However, the direct effect of modulating cell size on phage adsorption is unclear. To investigate the relationship between cell size and T4 phage adsorbed per cell, we used antisense inhibition of ftsZ, an essential cell division gene, in E. coli strain DH5α, to induce cell elongation. Induction of ftsZ antisense RNA resulted in a distinct cell shape morphology that is elongated and filamentous as a consequence of impaired cell division. We quantified T4 bacteriophage adsorption in elongated FtsZ deficient and normal length wildtype E. coli using double agar overlay plaque assay. We found that elongated cells adsorbed 16% more phage than wildtype cells. The elongated morphology and filamentation in E. coli with decreased ftsZ activity was visualized by crystal violet staining and phase contrast microscopy, which is consistent with the idea that T4 bacteriophage adsorption increases with E. coli cells that have greater surface area. Whether other methods of inducing elongated growth will increase bacteriophage adsorption, as well as its effects on subsequent steps of the bacteriophage life cycle, remain to be elucidated.